Boffins ponder Galileo signals as ocean monitors

It will be useful

Private enterprise might not know how to make any money from it, but academics are already thinking of uses for it. Yes, it is the Galileo system, Europe's answer to GPS.

Scientists at the University of Surrey, along with spin-out firm SSTL, have managed to detect the reflection of signals sent down from an orbiting prototype Galileo satellite.

The reflected signal was captured by the University's GPS Reflectometry Experiment. This hitched a lift into space back in 2003, aboard SSTL’s UK-DMC satellite. The aim was to demonstrate the use of GPS reflections to determine the roughness of the ocean, using a method called 'bistatic radar' or 'forward scatterometry'.

The same equipment has now detected a reflection from the prototype Galileo signal. It wasn't a huge amount of data: just 20 seconds' worth collected earlier this month. But the value is in the proof of concept, the scientists say.

"This is an important achievement in remote sensing and demonstrates the potential offered by Galileo for scientific purposes," said Dr Martin Unwin, Head of Global Navigation Satellite Systems at SSTL.

"Signals from Galileo... GPS and the Russian and Chinese systems, Glonass and Compass, can all be used as part of a new tool for ocean sensing. The future high bandwidth signals transmitted by Galileo, in particular, will enable higher resolution measurements of special interest to scientists, for example, in resolving wave heights."

He sad a constellation of small satellites - roughly 10kg each - could easily be launched to listen out for the echoes of publicly funded navigation signals. The size and simplicity of such a listening post means many satellites could be launched at a time, he added.

Data collected by such a system could help fill in gaps in forecast knowledge, giving better warning of storms far out at sea, as well as providing data for climate models. ®